Battery, battery plate assembly, and method of assembly

ABSTRACT

A battery plate assembly for a lead-acid battery is disclosed. The assembly includes a plates of opposing polarity each formed by an electrically conductive grid body having opposed top and bottom frame elements and opposed first and second side frame elements, the top frame element having a lug and an opposing enlarged conductive section extending toward the bottom frame element; a plurality of interconnecting electrically conductive grid elements defining a grid pattern defining a plurality of open areas, the grid elements including a plurality of radially extending vertical grid wire elements connected to the top frame element, and a plurality of horizontally extending grid wire elements, the grid body having an active material provided thereon. A highly absorbent separator is wrapped around at least a portion of the plate of a first polarity and extends to opposing plate faces. An electrolye is provided, wherein substantially all of the electrolyte is absorbed by the separator or active material. A method for assembling a battery is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority as a National Phase application fromInternational Patent Application Serial No. PCT/US2011/032498, filedApr. 14, 2011, entitled “Battery, Battery Plate Assembly, and Method ofAssembly,” which claims priority from United States Provisional PatentApplication, Ser. No. 61/323,988, filed Apr. 14, 2010 entitled“Battery,” the contents of each of which is incorporated herein byreference in its entirety.

FIELD

The present invention relates to the field of batteries (e.g. lead-acidbatteries including batteries for vehicle starting, lighting andignition applications; marine batteries; commercial batteries;industrial batteries; batteries for use with hybrid-electric vehicles,micro-hybrid vehicles, etc.). The present invention more specificallyrelates to the internal configuration of a lead acid battery withabsorbed electrolyte.

BACKGROUND

Lead-acid storage batteries are typically formed of several cellelements which are encased in separate compartments of a container withsulfuric acid electrolyte. Each cell element typically includes at leastone positive plate, at least one negative plate, and a separatorpositioned between each positive and negative plate. The positive andnegative plates are generally a lead or lead alloy grid that supports anelectrochemically active material, and in particular a lead basedmaterial (i.e., PbO, PbO₂, Pb or PbSO₄) pasted onto the grid. The gridsprovide an electrical contact between the positive and negative activematerials which serves to conduct current.

It is known to provide sealed lead-acid batteries of one or more cellsoperating on the oxygen cycle with internal recombination of oxygenduring charge and reasonable overcharge. These starved electrolytebatteries, or absorbed glass mat (AGM) batteries employ an absorptiveseparator mat preferably of micro-fine glass fibers having a largesurface area per unit of volume and a large porosity, enabling retentionof the bulk of the acid electrolyte (capacity determining) of the cellin the separator(s) while leaving a sufficiently thin layer ofelectrolyte on the active plate surface to sustain internal oxygenrecombination within the cell at high efficiencies. Unfortunately, AGMbatteries are more expensive than a typical flooded-cell type battery.In addition, such AGM batteries utilize expanded metal grids for thebattery plates which are concast or book mold cast grids. Such grids,and the plates, cells and batteries made therewith are inefficient. Inparticular, the use of expanded metal grids results in low efficiency inthe use of lead per performance output. Further, these expanded metalgrids, when used in combination with stamped or alternative grids,require additional tooling and devices for manufacture, resulting inincreased cost.

SUMMARY

Accordingly, a battery plate assembly for a lead-acid battery isprovided. The assembly includes a plate of a first polarity formed by anelectrically conductive grid body having opposed top and bottom frameelements and opposed first and second side frame elements, the top frameelement having a lug and an opposing enlarged conductive sectionextending toward the bottom frame element; a plurality ofinterconnecting electrically conductive grid elements defining a gridpattern defining a plurality of open areas, the grid elements includinga plurality of radially extending vertical grid wire elements connectedto the top frame element, and a plurality of horizontally extending gridwire elements, the grid body having an active material provided thereon.A plate of a second polarity opposite the first polarity is alsoprovided and formed by an electrically conductive grid body havingopposed top and bottom frame elements and opposed first and second sideframe elements, the top frame element having a lug and an opposingenlarged conductive section extending toward the bottom frame element; aplurality of interconnecting electrically conductive grid elementsdefining a grid pattern defining a plurality of open areas, the gridelements including a plurality of radially extending vertical grid wireelements connected to the top frame element, and a plurality ofhorizontally extending grid wire elements, the grid body having anactive material provided thereon. A highly absorbent separator iswrapped around at least a portion of the plate of a first polarity andextends to opposing plate faces. An electrolye is provided, whereinsubstantially all of the electrolyte is absorbed by the separator oractive material.

An alternative battery plate assembly is also provided. The assemblyincludes a plurality of plates of a first polarity formed by a stampedelectrically conductive grid body having opposed top and bottom frameelements and opposed first and second side frame elements, the top frameelement having a lug and an opposing enlarged conductive sectionextending toward the bottom frame element; a plurality ofinterconnecting electrically conductive grid elements defining a gridpattern defining a plurality of open areas, the grid elements includinga plurality of radially extending vertical grid wire elements connectedto the top frame element, and a plurality of horizontally extending gridwire elements, the grid body having an active material provided thereon.A plurality of plates of a second polarity opposite the first polarityare also provided and formed by a stamped electrically conductive gridbody having opposed top and bottom frame elements and opposed first andsecond side frame elements, the top frame element having a lug and anopposing enlarged conductive section extending toward the bottom frameelement; a plurality of interconnecting electrically conductive gridelements defining a grid pattern defining a plurality of open areas, thegrid elements including a plurality of radially extending vertical gridwire elements connected to the top frame element, and a plurality ofhorizontally extending grid wire elements, the grid body having anactive material provided thereon. A plurality of highly absorbentseparators are also provided. Each highly absorbent separator of theplurality of highly absorbent separators is wrapped around at least aportion of each plate in the plurality of plates of a first polaritysuch that the separator material is interleaved between adjacent plates.An electrolyte is provided, wherein substantially all of the electrolyteis absorbed by the plurality of highly absorbent separators or activematerial.

A method of assembling a battery is also provided. The method includesstamping a plurality of grids of a first polarity from a firstcontinuous strip of grid material, the stamped grids including anelectrically conductive grid body having opposed top and bottom frameelements and opposed first and second side frame elements, the top frameelement having a lug and an opposing enlarged conductive sectionextending toward the bottom frame element; a plurality ofinterconnecting electrically conductive grid elements defining a gridpattern defining a plurality of open areas, the grid elements includinga plurality of radially extending vertical grid wire elements connectedto the top frame element, and a plurality of horizontally extending gridwire elements. The method also includes stamping a plurality of grids ofa second polarity opposite the first polarity from a second continuousstrip of grid material, the stamped grids including an electricallyconductive grid body having opposed top and bottom frame elements andopposed first and second side frame elements, the top frame elementhaving a lug and an opposing enlarged conductive section extendingtoward the bottom frame element; a plurality of interconnectingelectrically conductive grid elements defining a grid pattern defining aplurality of open areas, the grid elements including a plurality ofradially extending vertical grid wire elements connected to the topframe element, and a plurality of horizontally extending grid wireelements. A plurality of plates of a first polarity are formed byproviding active material to the grids of a first polarity. A pluralityof plates of a second polarity are formed by providing active materialto the grids of a second polarity. A highly absorbent separator iswrapped around the bottom of each plate of a first polarity from theplurality of plates of a first polarity and extended upwardly along theopposing plate faces of each plate towards the lugs. The plurality ofplates of a first polarity and plurality of plates of a second polarityare assembled into a container so as to interleave highly absorbentseparator between each plate of a first polarity and each plate of asecond polarity. Electrolyte is provided to the container such thatsubstantially all of the electrolyte is absorbed by the plurality ofhighly absorbent separators or active material. The lugs of the batteryplates are coupled together by cast on straps, and the cast on strapsare coupled with terminal posts carried by the container.

BRIEF DESCRIPTION OF DRAWINGS

Various examples of embodiments of the systems, devices, and methodsaccording to the present disclosure will be described in detail, withreference to the following figures, wherein:

FIG. 1 is an isometric view of a vehicle including a battery accordingto one or more examples of embodiments;

FIG. 2 is an isometric view of a battery according to one or moreexamples of embodiments;

FIG. 3 is an isometric view of the battery shown in FIG. 2 without acover according to one or more examples of embodiments;

FIG. 4 is an isometric view of a cell including positive and negativeplates and separators from the battery shown in FIG. 3 according to oneor more examples of embodiments;

FIG. 5 is an isometric view of a cell including positive and negativeplates and separators from the battery shown in FIG. 3 according to oneor more examples of embodiments;

FIG. 6 is a detailed partial side elevation view of the cell from thebattery shown in FIG. 3 taken from segment 6-6 of FIG. 5 according toone or more examples of embodiments;

FIG. 7 is an isometric view of a cell including positive and negativeplates and separators from the battery shown in FIG. 3 according to oneor more examples of embodiments;

FIG. 8 is a detailed partial cross-sectional view of the cell from thebattery shown in FIG. 3 taken from segment 8-8 of FIG. 7 according toone or more examples of embodiments;

FIG. 9 is a plan view of a negative grid according to one or moreexamples of embodiments for use with the cell shown in FIG. 4;

FIG. 10 is a plan view of a positive grid according to one or moreexamples of embodiments for use with the cell shown in FIG. 4;

FIG. 11 is a plan view of a negative grid according to one or moreexamples of embodiments for use with the cell shown in FIG. 4, showingthe length or height of the negative grid and bottom frame element;

FIG. 12 is a plan view of a negative grid according to one or moreexamples of embodiments for use with the cell shown in FIG. 4, showingthe length and height of the negative grid and lug;

FIG. 13 is a plan view of a positive grid according to one or moreexamples of embodiments for use with the cell shown in FIG. 4, showingthe length or height of the positive grid and bottom frame element;

FIG. 14 is a plan view of a positive grid according to one or moreexamples of embodiments for use with the cell shown in FIG. 4, showingthe length or height of the positive grid and lug;

FIG. 15 is a plan view of a negative grid according to one or moreexamples of embodiments for use with the cell shown in FIG. 4;

FIG. 16 is a detailed partial cut-away view of the negative grid for usewith the cell shown in FIG. 4, taken from segment 16-16 of FIG. 15according to one or more examples of embodiments;

FIG. 17 is a plan view of a positive grid according to one or moreexamples of embodiments for use with the cell shown in FIG. 4;

FIG. 18 is a detailed partial cut-away view of the positive grid for usewith the cell shown in FIG. 4, taken from segment 18-18 of FIG. 17according to one or more examples of embodiments;

It should be understood that the drawings are not necessarily to scale.In certain instances, details that are not necessary to theunderstanding of the invention or render other details difficult toperceive may have been omitted. It should be understood, of course, thatthe invention is not necessarily limited to the particular embodimentsillustrated herein.

DETAILED DESCRIPTION

Referring to FIG. 1, a vehicle 102 is shown that includes a battery 104according to one or more examples of embodiments. While the vehicle 102is shown as an automobile, according to various alternative embodiments,the vehicle 102 may comprise any variety of types of vehicles including,among others, commercial trucks, motorcycles, buses, recreationalvehicles, boats, golf cars and carts, lawn and garden vehicles, and thelike. According to one or more examples of embodiments, the vehicle 102uses an internal combustion engine or a combination of an internalcombustion engine and battery for locomotive purposes. The battery 104may also be used for example in high performance engine starting, powersports, deep cycle, solar, storage, and the like.

The battery 104 shown in FIG. 1 is configured to provide at least aportion of the power required to start or operate the vehicle and/orvarious vehicle systems (e.g., starting, lighting and ignition systems).Further, it should be understood that the battery 104 may be utilized ina variety of applications not involving a vehicle, and all suchapplications are intended to be within the scope of the presentdisclosure.

The battery 104 shown in FIG. 1 may include any type of secondarybattery (e.g., rechargeable battery). According to one or more examplesof embodiments, the battery 104 is a lead-acid storage battery.Lead-acid storage batteries may be either sealed (e.g., non-maintenance)or unsealed (e.g., wet). According to one or more examples ofembodiments, the lead-acid storage battery 104 is a sealed lead-acidbattery.

An example of a lead-acid storage battery 104 is illustrated in FIGS.2-3. Referring to FIG. 3, the lead-acid storage battery 104 includesseveral cells or cell elements 106 which are provided in separatecompartments 108 of a container or housing 110 containing electrolyte.The illustrations provided herein relate to automotive applications,wherein groups of plates 106 are used in each of six stacks forproducing a standard automotive 12-volt battery. As shown in theillustrated example of FIGS. 3-8, a plurality of plates 112, 114(positive and negative) may be provided in a group 106. FIGS. 4-8illustrate seventeen plates (e.g. nine negative plates and eightpositive plates) in a group. However, it will be obvious to thoseskilled in the art after reading this specification that the size andnumber of the individual grids, the size and number of plates in anyparticular stack or group, and the number of stacks or groups used toconstruct the battery 104 may vary widely depending upon the desired enduse.

The battery housing 110 includes a box-like base or container 110 and ismade of a moldable resin. The container or housing 110 includes a frontwall 116, a rear wall 118, side walls 120 and a bottom wall 122. Thebattery compartment 108 also includes a front wall 124, end walls 126, arear wall 128 and a bottom wall 130. In the example described herein,five cell partitions or dividers 132 are provided between the side walls120, resulting in the formation of six compartments 108 (see FIG. 3), asmay be present in a 12-volt automotive battery. A plurality of plateblocks 106 are connected in series according to the capacity of the leadstorage battery 104 and are accommodated in the battery container orhousing 110 together with the electrolyte, which is most commonlyaqueous sulfuric acid. In various embodiments, a cell or plate block 106is located in each compartment 108. Each plate block 106 includes one ormore positive and negative plates 112, 114, each having at least one lug134, 136, and separator material 138 placed between each positive andnegative plate.

As shown in FIG. 2, a cover 140 is provided for the housing 110, and invarious embodiments, the cover 140 includes terminal bushings 142 andfill tubes to allow electrolyte to be added to the cells and to permitservicing. To help permit exhausting of gases generated during theelectrochemical reaction, a battery 104 may also include one or morevent cap assemblies.

One or more positive terminal posts 144 and one or more negativeterminal posts 146 may be found on or about the top 140 or front 116 ofthe battery 104. Such terminal posts 144, 146 typically include portionswhich may extend through the cover 140 and/or the front 116 of thebattery housing 110, depending upon the battery design. In variousembodiments, the terminal posts 144, 146 may also extend through aterminal post seal assembly to help prevent leakage of acid. It will berecognized that a variety of terminal arrangements are possible,including top, side or corner configurations known in the art. Eachterminal post 144, 146 may be coupled to a cast-on strap(s) 148, 150 ora connecting strap(s) that couple common polarity plates via extendedlugs 134, 136 or tabs in each cell.

As indicated, each cell element or chapter 106 includes one or morepositive plates 112, one or more negative plates 114, and a separator138 positioned between each positive and negative plate. Positive andnegative electrode plates 112, 114 can be classified into various typesaccording to the method of manufacturing the same. As one example, acell 106 including paste-type electrodes 112, 114 is shown in FIGS. 4-8.The paste-type electrode may include a grid substrate and anelectrochemically active material or “paste” provided on the substrate.The grid may be formed of a soft alloy. As can be seen in FIG. 4, eachplate 112, 114 may have a generally rectangular shape and includes a lug134 or 136 which, in the assembled battery 104, is electrically coupledto a battery terminal 144 or 146 using, for example a cast-on strap 148or 150. The plate 112, 114 also includes side walls 152, a bottom edge154, and opposing faces 156, 158.

As discussed above, the positive and negative plates 112, 114 eachcomprise a lead or lead alloy grid 160, 162 that supports anelectrochemically active material 164. The grids 160, 162 generallyprovide an electrical contact between the positive and negative activematerials or paste 164 which serves to conduct current. The grids 160,162 may also serve as a substrate for helping support electrochemicallyactive material (e.g., paste) deposited or otherwise provided thereonduring manufacture to form battery plates.

As set forth in greater detail below, known arts of lead acid batterygrid making include: (1) batch processes such as book mold gravitycasting; and (2) continuous processes such as strip expansion, stripstamping, continuous casting, and continuous casting followed byrolling. Grids made from these processes tend to have unique featurescharacteristic of the particular process and behave differently in leadacid batteries, especially with respect to the pasting process.

The grid or grids 160, 162 described herein are stamped grids. FIGS.9-18 illustrate one or more examples of embodiments of a stamped grid orgrids 160, 162, including grids for a positive plate 112 (e.g., FIG. 10)and a negative plate 114 (e.g., FIG. 9), one or more of which may beprovided with or include active material or paste (generally designatedby reference number 164) thereon. The examples shown in the Figuresinclude both a positive plate 112 and a negative plate 114 (see FIGS.4-8), as well as a positive grid 160 (e.g., FIG. 10) and a negative grid162 (e.g., FIG. 9). The stamped grid 160, 162 is an electricallyconductive grid body that has a frame which includes a top frame element166, 168, first side frame element 170, 172 and second side frameelement 174, 176, and a bottom frame element 178, 180. In variousembodiments, the stamped grid 160, 162 includes a series of electricallyconductive grid wires 184, 186, 188, 190, 192, 194 which define a gridpattern including open areas that help hold the active material or paste164 which helps provides current generation. In various embodiments, acurrent collection lug 134, 136 is integral with the top frame element166, 168. While FIGS. 9-18 depict the lug 134, 136 as offset from thecenter of the top frame element 166, 168, the lug 134, 136 mayalternatively be centered or positioned closer to either the first orsecond side frame elements 170, 174 or 172, 176. The top frame element166, 168 may include an enlarged conductive section 182, 183 at least aportion of which is directly beneath the lug 134, 136 to optimizecurrent conduction to the lug. The enlarged conductive section 182, 183extends toward the bottom frame element 178, 180. The bottom frameelement 178, 180 may be formed with one or more downwardly extendingfeet (not shown) for spacing the remainder of the grid away from thebottom of the battery container 110.

A series or plurality of radially extending vertical grid wires 184, 186or elements form part of the grid 160, 162. Vertical wire elements 184,186 are connected to the top frame element 166, 168 and the bottom frameelement 178, 180. One or more vertical wire elements 184, 186 are alsoconnected to the top frame element 166, 168 and the first side frameelement 170, 172 or the second side frame element 174, 176. Verticalwire element 188, 190 is parallel to the side frame elements 170, 172,174, 176. The remaining vertical wire elements 184, 186 extend radiallyfrom an imaginary intersecting point along a radius line running throughthe vertical elements. The vertical wire elements 184, 186 become closertogether when moving from the bottom frame element 178, 180 to the topframe element 166, 168 and get further apart when moving to the firstside frame element 170, 172 or the second side frame element 174, 176from the vertical element 188, 190.

The grid 160, 162 also includes a plurality of horizontal or cross wireelements 192, 194. To assist in supporting the electrochemical paste 164and/or permit the formation of paste pellets, in various examples ofembodiments, the stamped grid includes horizontal wires 192, 194 whichmay be equally spaced apart and are parallel to the top and/or bottomframe elements 166, 168, 178, 180. As shown in FIGS. 9-20, however, atleast some of the horizontal wires 192, 194 may not be equally spacedapart or parallel to the top and/or bottom frame elements.

Individual sections of the vertical wire elements 184, 186, 188, 190 andthe horizontal wire elements or the cross wire elements 192, 194 haveopposed ends which are joined at a plurality of nodes 196, 198 butdefine the open areas 200, 202 that support the electrochemical paste164 for conduction.

In various examples of embodiments, at least some of the grid wiresincrease in cross-sectional area along their length from bottom to topor have a tapered shape so as to optimize the current carrying capacityof the wires to help carry away increasing current being generated fromthe bottom to the top. The width and spacing of the wires between sideelements may be predetermined so that there are substantially equalpotential points across the width of the grid.

The cross-section of the grid wires may vary depending upon the gridmaking process. To help improve adhesion of the battery paste 164,however, in various embodiments, the grid wires may be mechanicallyreshaped or refinished. It should be appreciated that any number of gridwire shapes may be utilized as long as the shape provides suitable pasteadhesion characteristics. For example, the cross section of wires may beof any cross-section design including substantially oval shaped,substantially rectangular, substantially diamond shape, substantiallyrhomboid shape, substantially hexagon shape, and/or substantiallyoctagon shape.

In the battery grid 160, 162, each grid wire section may have adifferent cross-sectional configuration, or each grid wire section mayhave the same or a similar cross-sectional configuration. Depending onthe needs, a grid can be deformed at the vertical wire elements only,the horizontal wire elements only, or at both the vertical andhorizontal wire elements.

Various grid designs (e.g. stamped grid designs) may be utilized. See,e.g., U.S. Pat. Nos. 5,582,936; 5,989,749; 6,203,948; 6,274,274;6,921,611; 6,953,641; 7,398,581; 7,763,084; 7,767,347; 7,799,463; andU.S. patent application Ser. Nos. 10/819,485; 12/529,599; and60/904,404, each of which are incorporated herein by reference in theirentireties. Suitable stamped grids include PowerFrame® stamped grids(available from Johnson Controls, Inc., Milwaukee, Wis.) as the positivegrids and the negative grids. It should be noted that an infinite numberof grid designs may be utilized and therefore, it is not the intent ofthe description herein to limit the invention to the grid design shownin FIGS. 9-18, which are presented for the purposes of illustration.

Various chemistries in which the electrochemical potential betweenvarious materials is used to generate electricity have been studied andcommercially implemented. See, in general: Besenhard, J. O., Ed.,Handbook of Battery Materials, Wiley-VCH Verlag GmbH, Weinheim, Germany,1999; and Linden, D., Ed., Handbook of Batteries, Second Edition, McGrawHill Inc., New York, N.Y., 199, both of which are incorporated herein byreference.

The active material or paste 164 deposited on the grid is typically alead-based material (e.g. PbO, PbO₂, Pb or PbSO₄ at differentcharge/discharge stages of the battery) that is pasted, deposited orotherwise provided onto the grids 160, 162. The paste 164 compositionmay be determined by power requirements, cost and battery environment,as it is known in the art. In various embodiments, the active material164 of a lead-acid battery 104 is prepared by mixing lead oxide,sulfuric acid and water. The lead oxide reacts with the sulfuric acid toform mono-, tri- and/or tetrabasic lead sulfate(s). Dry additives, suchas fiber and expander, may also be added to the active material 164. Forexample, in various embodiments, expanders such as finely-dividedcarbons (e.g. lampblack or carbon black), barium sulfate and variouslignins may be included in the active material 164. In variousembodiments, the mixture is then dried and water is re-added to form apaste 164 of the desired consistency.

The active material or paste 164 provided on the negative grid 162 issimilar in type to the active material 164 provided on the positive grid160. However, it is contemplated there may be differences in the activematerial 164 depending upon the polarity of the grids for which it isintended to be provided. For example, the active material 164 providedon the positive grid 160 (e.g. lead dioxide [PbO₂]), may be provided inmicro-particle form, so that the electrolyte is allowed to diffuse andpermeate through the lead dioxide micro-particles on the positiveelectrode plate 112. The active material 164 of the negative grid 162may be porous and reactive, so that the electrolyte is allowed todiffuse and permeate through the lead on the negative electrode plate114. While specific examples are provided, variations thereon would notdepart from the overall scope of the present invention.

To prevent the separation of the active materials 164 from the grids160, 162 and to ensure easy handling of the active materials 164 in themanufacture of electrodes 112, 114, a pasting paper (not shown) may beadhered or otherwise provided on at least one of the surfaces of theactive material 164 as a support to the active material after depositionon the grids. Porous nonwoven fabric (e.g. having micron-sized pores),instead of paper, may alternatively be provided into the surface or onthe active material 164 to prevent the separation and handling problemsof the active material 164 and initial high rate discharge degradation.For example, a nonwoven fabric synthesized from thermoplastic resin byspun-bonding or thermal-bonding may be used. In various embodiments,nonwoven fabric formed of one or more polyesters, polypropylenes, orviscose rayon may be used.

In various examples of embodiments, one or more battery separators 138are used to conductively separate the positive electrodes 112 andnegative electrodes 114. A separator material 138, utilized to separateadjacent plates 112, 114 from one another, has sufficient porosity andretention to contain substantially all of the electrolyte necessary tosupport the electrochemical reactions. In various examples ofembodiments, the separator material 138 is compressible so that uponstacking of the elements, the separator material substantially conformsto the contour of the surface of the plates 112, 114 to help it performits wicking or capillary action.

The separator 138 of one or more examples of embodiments is a highlyporous mat of ultrafine glass fibers and has properties for use insealed lead-acid batteries operating on the oxygen recombinationprinciple. The separator 138 described herein is adapted to provide forhydrogen and oxygen recombination inside the battery 104, and mayinclude gas phase transfer of oxygen to the negative plates 114 toenable recombination back into water with charging. Generally, theseparator 138 or mat is formed of a material that allows the electrolyteto be suspended in close proximity with the plates' active material 164and may absorb electrolyte through capillary action. In various examplesof embodiments, the separator 138 is constructed of absorbent glass mat(AGM). The mat 138 preferably includes a polymeric component, such aspolypropylene and/or polyethylene. In various examples of embodiments,the AGM or separator 138 is non-woven or a non-woven fabric, andincludes glass micro-fibers which may retain electrolyte (e.g. bycapillary action) and provide gas spaces when the grid is not fullysaturated with electrolyte. In this regard, the electrolyte may be freeto move but is more confined than in a flooded cell. Other known andlater developed separator materials may also or alternatively be used inconnection with the cell including, without limitation, micro-porousrubber, polyvinyl chloride, polyolefin and phenolic resin impregnatedpaper.

As shown in FIGS. 5-8, in various embodiments, separator 138 may beplaced on the plate and/or between the plates 112, 114. Separators 138may be provided between the plates 112, 114 to prevent shorting and/orundesirable electron flow produced during the reaction occurring in thebattery 104. In one or more examples of embodiments, the separatormaterial 138 may be wrapped under and/or around certain plates 112 or114 (e.g. plates of a similar polarity). In the illustrated examples,separator material 138 is wrapped or partially wrapped around thepositive plate(s) 112 or a portion thereof, although the separator 138may be wrapped or partially wrapped around the negative plate(s) 114 ora portion thereof without departing from the overall scope of thepresent invention. For example, separator material 138 may be wrappedaround the bottom edge 154 of a plate 112 and extend upwardly along theopposing plate faces 156, 158 towards the lug 134 to substantially orpartially separate the plate 112 from adjoining plates 114, such asplates of opposite polarity 112 and 114.

In each cell, it is preferable that there is essentially no or verylittle free electrolyte except that retained within the separatormaterial 138 or in any pores of the plates 112, 114. However, it iscontemplated that not all of the electrolyte will be absorbed by theseparator 138 and thus some free electrolyte will or may exist in thecell. In various embodiments, the separator material 138 surrounds anedge 154 (e.g. the edge formed in part by the lower frame element) ofone or more plates and may contact at least one interior surface of thecontainer 110.

The thickness of a separator 138 will vary depending upon the type ofbattery 104 in which it is used. In various embodiments, the thicknessof the separator 138 may range from 0.01 millimeters to 2.00 millimeteror more is approximately 1.65 millimeters (0.065 inches).

In one or more alternative examples of embodiments, the grids 162 of theplates 114 adjoining the plates 112 wrapped with separator material 138are longer or taller than the grids 160 of the plates 112 wrapped withseparator material 138 (see FIGS. 5-8 and 11-18). As a result, the lugs136 of the plates adjoining the plates wrapped with separator material138 (i.e., those plates that are not wrapped) are at a substantiallysimilar or uniform height to the lugs 134 of the plates wrapped withseparator material 138. The substantially uniform lug height may beachieved through a variety of ways. For example, as shown in FIGS. 9-18,the margin (X) (see FIGS. 16, 18) of the bottom frame element 180 of oneor more grids 162 of the plates 114 adjoining a plate 112 wrapped with aseparator 138 (e.g. one or more negative plates) may be made relativelythicker than the bottom frame element 178 of the grid 160 for plate 112wrapped with the separator 138 providing a plate height such that lugheight of plates 112 wrapped with a separator 138 is substantially thesame as the lug height of plates 114 that are not wrapped with aseparator 138. In this regard, the grids may be provided with thefollowing ratios (referring to FIGS. 11-14):

-   plate height (A¹)<plate height (B¹)-   lug height (A²)<lug height (B²); but-   lug height (A²)+separator thickness=lug height (B²)

In various embodiments, and as shown in FIGS. 5-8, the increase inrelative thickness is substantially equal to the thickness of theseparator material 138. In various embodiments, and as shown in FIGS.11-18, the thickness of the bottom frame element 180 of one or moregrids 162 of the plates 114 adjoining a plate 112 wrapped with aseparator 138 (e.g. one or more negative grids) may be betweenapproximately 1.25 millimeters and 1.75 millimeters thicker than thebottom frame element 178 of the grids 160 for plates 112 wrapped withthe separator 138. In the illustrated example, the positive grid 160 andplate 112 are shown with separator 138 wrapped thereon for ease ofreference and understanding, but alternatively the negative grid 162 andplate 114 may have the separator 138 thereon as noted herein.

A plate 112, 114 for a lead-acid battery 104 is made by applying activematerial or paste 164 to a conductive support such as a lead alloy grid160, 162. Plates can be classified according to the method ofmanufacturing the same. The grids 160, 162 may be produced using variousknown or later-developed processes. For example, as discussed above, thesubstrate 160, 162 may be formed by a casting process (e.g. by pouring amelted alloy into a mold), a stamping process, or by continuous rolling.In the method of assembling a battery 104 according to one or moreexamples of embodiments described herein, a plurality of positive grids160 having the grid pattern described herein are formed by stamping theplurality of grids from a rolled wrought strip of grid material. Aplurality of negative grids 162 having the grid pattern described hereinare also formed by stamping the plurality of grids from a rolled wroughtstrip of grid material. During the manufacture of the grids 160, 162 orthe plates 112, 114, the grid wires may be refinished or reshaped.

The active material or paste 164 is then applied to, deposited on orotherwise provided (e.g. pasted by a conventional paster) on the grid160, 162 to form the plates 112, 114. The paste 164 may be applied suchthat paste 164 may be provided on substantially all of the grid,including the edges or margins, filling the holes therein as well asforming a coat on each face or side. Alternatively, the marginal edgesand the lugs 134, 136 are substantially free from paste 164. In variousembodiments, one or more pasting materials or pasting papers areprovided on one or both surfaces of the active material 164. In variousembodiments, the pasting materials or paper may be provided in acontinuous process.

In various examples of embodiments, the grids 160, 162, active material164 and pasting material or paper are fed to a divider where the stripis cut into plates 112, 114. Plates cut from the strip may be flattenedor otherwise modified to help smooth out any uneven regions of paste.

Groupings of individual battery plates 112 or 114 may be assembled,enveloped, interleaved or otherwise separated with separator material138, and provided together to form plate sets 106. For example, unformedplates 112, 114 may be assembled with interleaved highly absorbentseparators 138 or AGM separator material, pressed to a desired pressure,if necessary, and inserted into the container 110 with the plates andseparators 138 existing under mutual compression. In various examples ofembodiments, the AGM material or separator 138 is wrapped around a plate112 or 114 as shown in FIGS. 4-8. For example, the AGM material may bewrapped around the bottom edge 154 of each positive plate 112 and extendupwardly along the opposing plate faces 156, 158 of each positive plate112 towards the lugs 134. The AGM material 138 may cover a portion ofthe plate 112 or a substantial portion of the plate.

During assembly, the positive lugs 134 of the battery plates 112 arecoupled together and the negative lugs 136 of the battery plates 114 arecoupled together. This may be accomplished using cast-on straps 148, 150formed by taking assembled battery stacks 106, inverting them, anddipping the lugs 134, 136 into molten lead provided in a mold. To permitcurrent to follow throughout the battery 104, cast-on straps 148 or 150of stacks 106 are joined or coupled. Moreover, terminal electrodes orposts 144, 146 are provided which extend through the cover 140 orhousing 110 or into bushings 142 or the like in the cover 140 or housing110 to permit electrical contact with a vehicle's electrical system orother system requiring or intended to use battery power. The cast-onstraps 148 or 150 are coupled to the respective terminal posts 144 or146.

In various embodiments, the battery housing 110, including the cover140, is provided containing the battery cells in which the various plategroupings 106 with separator 138 are added to the individualcompartments 108 of the container 110. In various embodiments,electrolyte is then added to the battery cells. The electrolyte isprovided in a controlled quantity so that the electrolyte issubstantially, fully absorbed in the pores of the plates 12, 114 and theseparator 138. Any residual electrolyte fluid coating, dust, and otherdebris may be washed away to prepare the battery 104 for shipment.

Following the initial wash, the batteries are electrochemically formedby passage of current through the battery 104, and in particular thecells and electrodes, for example to convert the lead sulfate or basiclead sulfate(s) to lead dioxide (positive plates) or lead (negativeplates). This is referred to as the “formation” process. Formation mayoccur prior to sealing the cover 140 to the container 110 or aftersealing.

The battery, plates, grids, and separator provided herein providevarious advantages over traditional devices. The battery describedherein also provides a high specific power or power density and have alow internal resistance which allows for rapid charge and discharge. Thebattery, plates, grids and separator provided herein for use withabsorbent mat batteries provide more efficient use of lead perperformance output. In addition, the battery may include purer lead inthe plates as each plate does not need to support its own weight and theplates are resistant to vibration due to the sandwich constructioncaused by the use of AGM matting. Further, the battery, including theabsorbent matting, retains fluid, reducing the likelihood of a spill ofelectrolyte from the battery and conserving water. Moreover, thesuspension of electrolyte in close proximity with the plates' activematerial enhances both the discharge and recharge efficiency of thebattery.

Use of the same form of grid, i.e. a stamped grid, or the use of astamped rolled wrought strip for making the grids for an absorbent matbattery reduces costs (e.g., tooling costs, among other costs), as itpermits shared tooling for positive and negative plates in, for example,an AGM battery, and eliminates the need for concast or book mold castgrids.

The secondary absorbent glass mat (AGM) battery, or the like, of a typedisclosed in the present application includes one or more stamped gridsdescribed herein as the positive grids and the negative grids whichimprove current flow, performance, life and/or corrosion capabilities ofthe battery. The use of one or more stamped grids described herein asthe positive grids and the negative grids also reduces the weight and/orthe amount of conductive material (e.g. lead) in the battery, improvesthe rigidity and reduces shorting of the grids in the battery. Inaddition, the use of one or more stamped grids described herein as thepositive grids and the negative grids eliminates expanded metal and/orcast grids from the manufacturing process, thereby improvingmanufacturing processes and reducing material and/or manufacturing costs(e.g. by allowing the use of the same stamping equipment, such as withonly small changes or modifications to the equipment) to manufactureboth positive and negative grids. Moreover, the use of one or morestamped grids described herein that are extended (e.g. in height)relative or compared to at least one corresponding opposite polaritystamped grid helps maintain a substantially relative uniform lug heightbetween positive and negative plates or electrodes including suchstamped grids.

As utilized herein, the terms “approximately,” “about,” “substantially”,and similar terms are intended to have a broad meaning in harmony withthe common and accepted usage by those of ordinary skill in the art towhich the subject matter of this disclosure pertains. It should beunderstood by those of skill in the art who review this disclosure thatthese terms are intended to allow a description of certain featuresdescribed and claimed without restricting the scope of these features tothe precise numerical ranges provided. Accordingly, these terms shouldbe interpreted as indicating that insubstantial or inconsequentialmodifications or alterations of the subject matter described and claimedare considered to be within the scope of the invention as recited in theappended claims.

It should be noted that references to relative positions (e.g., “top”and “bottom”) in this description are merely used to identify variouselements as are oriented in the Figures. It should be recognized thatthe orientation of particular components may vary greatly depending onthe application in which they are used.

For the purpose of this disclosure, the term “coupled” means the joiningof two members directly or indirectly to one another. Such joining maybe stationary in nature or moveable in nature. Such joining may beachieved with the two members or the two members and any additionalintermediate members being integrally formed as a single unitary bodywith one another or with the two members or the two members and anyadditional intermediate members being attached to one another. Suchjoining may be permanent in nature or may be removable or releasable innature.

It is also important to note that the construction and arrangement ofthe battery or electrodes or separator as shown and described in thevarious examples of embodiments is illustrative only. Although only afew embodiments have been described in detail in this disclosure, thoseskilled in the art who review this disclosure will readily appreciatethat many modifications are possible (e.g., variations in sizes,dimensions, structures, shapes and proportions of the various elements,values of parameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter recited. For example,elements shown as integrally formed may be constructed of multiple partsor elements show as multiple parts may be integrally formed, theoperation of the interfaces may be reversed or otherwise varied, thelength or width of the structures and/or members or connector or otherelements of the system may be varied, the nature or number of adjustmentpositions provided between the elements may be varied (e.g. byvariations in the number of engagement slots or size of the engagementslots or type of engagement). The order or sequence of any process ormethod steps may be varied or re-sequenced according to alternativeembodiments. Other substitutions, modifications, changes and omissionsmay be made in the design, operating conditions and arrangement of thevarious examples of embodiments without departing from the spirit orscope of the present inventions.

What is claimed is:
 1. A battery plate assembly for a lead-acid batterycomprising: a plate of a first polarity formed by an electricallyconductive grid body having opposed top and bottom frame elements andopposed first and second side frame elements provided about a pluralityof interconnecting electrically conductive grid elements defining a gridpattern having a plurality of open areas, the grid elements including aplurality of radially extending vertical grid wire elements originatingfrom the top frame element, and a plurality of horizontally extendinggrid wire elements extending between the side frame elements, the bottomframe element having a first margin, and the top frame element having afirst lug; and a plate of a second polarity opposite the first polarityformed by an electrically conductive grid body having opposed top andbottom frame elements and opposed first and second side frame elementsprovided about a plurality of interconnecting electrically conductivegrid elements defining a grid pattern having a plurality of open areas,the grid elements including a plurality of radially extending verticalgrid wire elements originating from the top frame element, and aplurality of horizontally extending grid wire elements extending betweenthe side frame elements, the bottom frame element having a secondmargin, and the top frame element having a second lug, wherein thesecond margin is greater than the first margin such that when the plateof a first polarity is wrapped with a separator, the first lug isaligned with the second lug.
 2. The battery plate assembly of claim 1,wherein the plate of a first polarity is a positive plate.
 3. Thebattery plate assembly of claim 1, further comprising: an absorbentglass mat separator wrapped around at least a portion of the plate of afirst polarity and extending between a face of the plate of a firstpolarity and an opposing face of the plate of a second polarity; anactive material provided on the grid body of the plate of a firstpolarity and on the grid body of the plate of a second polarity; and anelectrolyte, wherein substantially all of the electrolyte is absorbed bythe separator or active material.
 4. The battery plate assembly of claim1, wherein a portion of the bottom frame element of the plate of a firstpolarity is received by a separator such that the separator extendsupwardly along a plate face defined by the grid body toward the firstlug.
 5. The battery plate assembly of claim 4, wherein the first marginof the plate of a first polarity and the separator have a combinedheight in a first direction which corresponds to a height of the secondmargin of the plate of a second polarity in a first direction such thatthe second lug of the plate of a second polarity is at a substantiallyuniform height to the first lug of the plate of a first polarity whenthe plates of a first polarity and second polarity are provided in abattery, the first direction being from the bottom frame element towardthe top frame element of a plate.
 6. A battery comprising the batteryplate assembly of claim
 1. 7. A battery plate assembly comprising: aplurality of plates of a first polarity formed by an electricallyconductive grid body having opposed top and bottom frame elements andopposed first and second side frame elements, the top frame elementseach having a first lug, the frame elements defining the perimeter of aplurality of interconnected grid elements forming a grid pattern havinga plurality of open areas, the grid elements including a plurality ofradially extending vertical grid wire elements connected to the topframe element, and a plurality of horizontally extending grid wireelements, the plates of a first polarity each having a first plateheight extending between the top frame element and the bottom frameelement; and a plurality of plates of a second polarity opposite thefirst polarity formed by an electrically conductive grid body havingopposed top and bottom frame elements and opposed first and second sideframe elements, the top frame elements each having a second lug, theframe elements defining the perimeter of a plurality of interconnectedgrid elements forming a grid pattern having a plurality of open areas,the grid elements including a plurality of radially extending verticalgrid wire elements connected to the top frame element, and a pluralityof horizontally extending grid wire elements, the plates of a secondpolarity each having a second plate height extending between the topframe element and the bottom frame element, wherein the second plateheight is greater than the first plate height.
 8. The battery plateassembly of claim 7, wherein the bottom frame elements of each of theplates of a first polarity include a first margin having a height fromthe bottom frame element toward the top frame element, the bottom frameelements of each of the plates of a second polarity include a secondmargin having a height from the bottom frame element toward the topframe element, the height of the second margin being greater than theheight of the first margin.
 9. The battery plate assembly of claim 7,wherein a portion of each of the plates of a first polarity is receivedby a separator, the combined first plate height and separator for eachof the plates of a first polarity is approximately equal to the secondplate height for each of the plates of a second polarity such that thesecond lugs of the plurality of plates of a second polarity are at asubstantially uniform height to the first lugs of the plates of a firstpolarity received by the separator.
 10. A battery comprising the batteryplate assembly of claim
 7. 11. The battery plate assembly of claim 1,wherein: the first margin is a thickness of the bottom frame element ofthe plate of a first polarity defined by a distance between a first edgeof the bottom frame element and a second edge of the bottom frameelement, the first edge being furthest away from the top frame elementand the second edge being closest to the top frame element; and thesecond margin is a thickness of the bottom frame element of the plate ofa second polarity opposite the first polarity defined by a distancebetween a first edge of the bottom frame element and a second edge ofthe bottom frame element, the first edge being furthest away from thetop frame element and the second edge being closest to the top frameelement.
 12. The battery plate assembly of claim 11, wherein thethickness of the second margin is between approximately 1.25 mm and 1.75mm thicker than the thickness of the first margin.
 13. The battery plateassembly of claim 1, wherein the plate of a first polarity has a firstplate height defined as a distance from the bottom frame element to thetop frame element, the plate of a second polarity has a second plateheight defined as a distance from the bottom frame element to the topframe element, the second plate height being greater than the firstplate height.
 14. The battery plate assembly of claim 13, wherein thefirst plate height is further defined as a distance from a portion ofthe bottom frame element furthest away from the top frame element to aportion of the top frame element furthest away from the bottom frameelement, and the second plate height is further defined as a distancefrom a portion of the bottom frame element furthest away from the topframe element to a portion of the top frame element furthest away fromthe bottom frame element.
 15. The battery plate assembly of claim 13,wherein a portion of the bottom frame element of the plate of a firstpolarity is received by a separator, the first plate height and theseparator have a combined height which is approximately equal to thesecond plate height.
 16. The battery plate assembly of claim 1, whereinthe plate of a first polarity has a first lug height defined as adistance from the bottom frame element to an edge of the first lugfarthest away from the top frame element, and the plate of a secondpolarity has a second lug height defined as a distance from the bottomframe element to an edge of the second lug farthest away from the topframe element, the second lug height being greater than the first lugheight.
 17. The battery plate assembly of claim 16, wherein a portion ofthe bottom frame element of the plate of a first polarity is received bya separator, the first lug height and the separator have a combinedheight which is approximately equal to the second lug height.
 18. Abattery plate assembly for a lead-acid battery comprising: a plate of afirst polarity formed by an electrically conductive grid body havingopposed top and bottom frame elements and opposed first and second sideframe elements, the frame elements provided about a plurality ofinterconnecting electrically conductive grid elements defining a gridpattern, the grid pattern having a plurality of open areas formed by aplurality of radially extending vertical grid wire elements coupled tothe top frame element, and a plurality of horizontally extending gridwire elements extending between the side frame elements, the top frameelement having a first lug, and having a first lug height extending froma portion of the first lug furthest away from the top frame element to aportion of the bottom frame element furthest away from the top frameelement; and a plate of a second polarity opposite the first polarityformed by an electrically conductive grid body having opposed top andbottom frame elements and opposed first and second side frame elements,the frame elements provided about a plurality of interconnectingelectrically conductive grid elements defining a grid pattern, the gridpattern having a plurality of open areas formed by a plurality ofradially extending vertical grid wire elements coupled to the top frameelement, and a plurality of horizontally extending grid wire elementsextending between the side frame elements, the top frame element havinga second lug, and having a second lug height extending from a portion ofthe second lug furthest away from the top frame element to a portion ofthe bottom frame element furthest away from the top frame element,wherein the second lug height is greater than the first lug height. 19.The battery plate assembly of claim 18, wherein the bottom frame elementof the plate of a first polarity includes a first margin having a heightfrom the bottom frame element toward the top frame element, the bottomframe element of the plate of a second polarity includes a second marginhaving a height from the bottom frame element toward the top frameelement, the height of the second margin being greater than the heightof the first margin.
 20. The battery plate assembly of claim 18, whereina portion of the plate of a first polarity is coupled to a separator andthe combined height of the first lug height and the separator isapproximately equal to the second lug height of the plate of a secondpolarity such that the first lug and second lug are provided atsubstantially the same height when the plate of a first polarity and theplate of a second polarity are provided in a battery.